Identification, friend or foe, (IFF) has been primarily related in the past to air surveillance radar and related transponder systems; however, it has recently been recognized that there is a need for battlefield identification equipment for ground personnel who could be assigned a squad or a company level. The need for such equipment is made imperative by the problem of discrimination between enemy and friend which is fundamental to every type of conflict including battlefield warfare. The conventional IFF approach used with air surveillance radars is inappropriate for battlefield conditions since that approach requires a complex L-band transmitter and antenna system, is over-sophisticated for the battlefield environment, and would be extremely difficult to reduce in size, weight, and cost to satisfy the man-portable requirements. Electronic and other non-visual techniques for achieving identification have not yet been used operationally by battlefield personnel.